Linear mixed-effects models of seasonal Cape gannet behavioural patterns at Bird Island, Algoa Bay.

Constructed using log-transformed foraging trip (T) and nest attendance (N) durations as a function of predictor variables during the breeding (August to February) and non-breeding (March to July) seasons: adult sex, time of bout initiation, chick age reflected as breeding stage (see Methods), month of bout initiation, chick age interacting with adult sex, as well as average meteorological parameters over the bout duration which included rainfall, prevailing wind direction, wind speed, and wind speed interacting with direction. Number of parameters for each model (np) and Akaike Information Criterion (AIC) scores, the AIC difference from the most parsimonious model (ΔAIC) as well as the marginal and conditional R2 (variance explained by fixed and both fixed and random effects respectively [47]) are indicated. Of the models generated from all permutations of predictor variables, the six with the lowest AIC scores are presented. Black dots and empty spaces indicate variables incorporated or not incorporated in models whereas dashes indicate that the variable was not considered.